GSM SIM 800L Don't send message

Hello everyone!
I need help with my SIM 800L, because it didnt arrive to my phone… So this is the code

#include "SIM900.h"
#include <SoftwareSerial.h>
//If not used, is better to exclude the HTTP library,
//for RAM saving.
//If your sketch reboots itself proprably you have finished,
//your memory available.
//#include "inetGSM.h"

//If you want to use the Arduino functions to manage SMS, uncomment the lines below.
#include "sms.h"
SMSGSM sms;

//To change pins for Software Serial, use the two lines in GSM.cpp.

//GSM Shield for Arduino
//www.open-electronics.org
//this code is based on the example of Arduino Labs.

//Simple sketch to send and receive SMS.

int numdata;
boolean started=false;
char smsbuffer[160];
char n[20];

void setup() 
{
  //Serial connection.
  Serial.begin(9600);
  Serial.println("GSM Shield testing.");
  //Start configuration of shield with baudrate.
  //For http uses is raccomanded to use 4800 or slower.
  if (gsm.begin(2400)){
    Serial.println("\nstatus=READY");
    started=true;  
  }
  else Serial.println("\nstatus=IDLE");
  
  if(started){
    //Enable this two lines if you want to send an SMS.
   if (sms.SendSMS("+34*********", "Arduino SMS"))
      Serial.println("\nSMS sent OK");
  }

};

void loop() 
{
  if(started){
    //Read if there are messages on SIM card and print them.
    if(gsm.readSMS(smsbuffer, 160, n, 20))
    {
      Serial.println(n);
      Serial.println(smsbuffer);
    }
    delay(1000);
  }
};

First of all, I only get from Serial, Not Resp, but I trying quit one GND, and it dissipate less and function, but now, the problem is based on the Not receiving SMS.

Because the serial send Now this message:

GSM Shield testing.
DB:ELSE
DB:ELSE
DB:ELSE
DB:CORRECT BR

status=READY
DEBUG:SMS TEST

SMS sent OK

Mounting Information:

Board: Arduino Mega 2650
Modem GSM SIM800L
Connection:
5 V → 5 V arduino Board
Gnd → AIR
Gnd → Gnd arduino Board
Rst → AIR
SIM TXD → Pin 51
SIM RXD → Pin 50
VDD → AIR


I use the connection 50 to TXD and 51 to RXD, and verified that it isnt the problem. So I am lost now, and i dont know how to fix this problem.

I will be so pleased with your help,
Thank you very much
Have a good day!

Hello Lord Edwen Winston, I am Edwen of the future, I have solved the problem by my self, and return here to explain someone who come with the same fail.

First of all, the code is ok, so we dont have to change it. Secondly, this problem is based on the connection, we have to connect all the gnd, to the ground, and connect a power supply that give us 5V DC, and connect the ground also to the ground to our arduino MEGA, so the Arduino and the DC power will have the same ground.

So then the problem will be solved.